Kyoketsu-shoge

The kyoketsu-shoge (距跋渉毛), which means "to run about in the fields and mountains", is a double edged blade, with another curved blade attached near the hilt at a 45-60 degree angle. This is attached to 12 to 18 feet of rope, chain, or hair which then ends in a large metal ring. It is thought to have developed before the more widely known kusarigama (sickle and chain). Ninja were usually of the peasant class and the blade of the kyoketsu-shoge was originally a farming tool.

Almost exclusively used by the ninja, the kyoketsu-shoge had a multitude of useful applications. The blade could be used for pulling slashes as well as thrusting stabs. The chain or cord, sometimes made from human hair or horsehair for strength and resiliency, could be used for climbing, ensnaring an enemy, binding an enemy and many such other uses. The long range of the weapon combined a cutting tool along with the capability to strike or entangle an enemy at what the user perceived to be a 'safe' distance out of the way. When skilled with this weapon it could be used to entangle a sword and rip it from the opponents hands rendering him harmless. The kyoketsu-shoge cord and ring was sometimes used to wrap around an enemy's legs and trip them.

Typically the round ring was flat rather than round in cross section to provide a firmer grip and a more sturdy frame, as the ring was also used for strikes and deflective blows in use. This tool was also used as a climbing aid, and it could be thrown and lodged in corners.

...
Wikipedia